Intracorporeal vascular prosthetic blood irradiator



April ,1970 J. HELLERSTEIN T AL 3,505,991

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---- r 1 1 v I I I I I I I I I I I- W 7 United States Patent O 3,505,991 INTRACORPOREAL VASCULAR PROSTHETIC BLOOD IRRADIATOR Lewis J. Hellerstein and Lloyd W. Johnston, San Antonio,

Tex., assignors to the' United States of America as represented by the Secretary of the Air Force Filed Feb. 13, 1968, Ser. No. 705,041 Int. Cl. A61b 6/00; A6111 /01; G21h5/00 U.S. Cl. 1281.1 5 Claims ABSTRACT OF THE DISCLOSURE A tube for replacing a segment of vein or artery has a Window and passes through a double shield having a hollowed out portion communicating with the window. A radioactive element is disposed in the hollowed out portion and is movable by a positioning means whereby the amount of radiation received by the blood may -be varied.

BACKGROUND OF THE INVENTION The present invention pertains to devices for treating diseases, wounds and other abnormal conditions in humans and animals by applying radioactive substances to the body and more particularly, as in this instance, to the blood.

One manner used in the prior art to apply radioactive substances to the blood was to inject small sources or pieces of the radioactive material in the blood stream and to allow these pieces to be absorbed by bone marrow and lymphatic organs. Another manner used an intracorporeal or extracorporeal prosthetic tube with the radioactive substance attached to or surrounding the tube. As the blood was pumped through the tube, it was subjected to the radiation. The prior art devices and methods suffered from the incapability of continuously irradiating the blood for long periods and from being unable to adjust the dose during treatment without reopening of the skin or having a continual opening in the skin.

BRIEF SUMMARY OF THE INVENTION The device of the present invention is a vascular prosthesis put in the body in place of a segment of an artery or vein. The prosthesis comprises a tube having a window made from a substance that allows radiation to penetrate into the interior of the tube. Around the tube is an inner and outer shield having an enlarged hollowed out portion next to the window. A radioactive element is disposed in the hollowed out portion and is connected to a positioning means whereby said radioactive element may be positioned directly adjacent to said window or moved away from the window at which position the particulate radiation is absorbed in the inner shield. A number of intermediate positions may be utilized, thus varying the amount of radiation passing through said window into said tube. The said outer shield will absorb most of the Bremsstrahlung produced by interaction of said particulate radiation with said inner shield. The outer shield is enclosed in a coating of a material that is inert to the body.

Accordingly, the objects of this invention are to provide a device for irradiating blood that may be permanently implanted in the patient without repeated or continuous skin openings, to provide a blood irradiator where the dose of radiation given to the blood may be varied and to give minimal radiation to tissue surrounding the blood irradiator.

BRIEF DESCRIPTION OF THE DRAWINGS The features of the invention are better understood from the following description of a specific embodiment 3,505,991 Patented Apr. 14, 1970 "ice DESCRIPTION OF A SPECIFIC EMBODIMENT Referring now to FIGURE 1, an intracorporeal vascular prosthetic blood irradiator 10 is shown having a hol low tube 11 through which blood is to flow. As shown in FIGURES 2 and 3, an opening in the wall of tube 11 contains a window 12 made from a substance that will allow radiation from a radioactive element to pass into the interior of tube 11. The tube 11 is made from a material inert to the body, and materials for this purpose include titanium, silicone rubber and a synthetic fiber sold under the trademark Dacron. Window 12 may be a thin layer of stainless steel. A shield 13 surrounds tube 11 and has an enlarged hollowed out portion 14 communicating with window 12. Hollowed out portion 14 contains radioactive element 15, an example of which is Sr-Y in secular equilibrium. Shield 13 is composed of two parts, interior part 16 surrounded by exterior part 17. Interior part 16 is made from a material which is used to stop the beta particles emitted from radioactive element 15 except those that pass through Window 12 into the blood. Exterior part 17 is made from a material which will reduce the Bremsstrahlung radiation produced in stopping the beta particles. Materials that may be used for interior part 16 include aluminum, graphite, and plastic, such as polystyrene, while materials for exterior part 17 include lead and tantalum. Around shield 13 is a coating 19 of material inert to the body. A material preferred for coating 19 is an adhesive sealant made of silicone rubber and sold under the trademark Silastic by the Dow Corning Corporation. For this described positioning means, shield 13 has a cavity 21 on its exterior surface. A tunnel 22 extends through shield 13 from cavity 21 to the enlarged hollowed out portion 14. Radioactive element 15 is attached by support 23 to cable 24 which extends in tunnel 22 from cavity 21 to hollowed out portion 14. A handle 27 is attached to cable 24 in cavity 21 to facilitate moving the radioactive element 15.

Operation and use of the device shown in the drawing is as follows: The device is placed in the body of a patient with handle 27 lying immediately under the skin. The two ends of tube 11 are attached in place of a segment of artery or vein allowing the patients blood to pass through tube 11. With handle 27 in the position shown in dotted outline in FIGURE 2 the blood receives radiation from radioactive element 15, shown in dotted outline, through window 12. If it is desired to discontinue the radiation, handle 27 is moved to the position shown in solid in FIGURE 2 by palpation through the skin, which pulls radioactive element 15 away from window 12 by means of cable 24. It is obvious that by moving handle 27 to various positions in cavity 21 the amount of radiation received by the blood can be varied.

Other types of positioning mechanisms would include magnetic whereby a magnet would be attached to the cable 24,. or a disc, or a drum, or an arm which would be attached to said radioactive element, and said radioactive element be moved by manipulation of an external magnetic unit. Alternatively, cavity 21 could be replaced 'by a small piston mechanism with a valve and the radioactive element 21 and support 23 be positioned hydraulically. Finally an electronic mechanism could be devised such that a small solenoid would move a disc, drum, arm, or cable attached to said radioactive element. The solenoid would be activated by a sensor responsive to an R-F transmitter.

The above described movement mechanisms, i.e. handle with a cable, magnetic drive, hydraulic drive, or electronic are all self-contained in the blood irradiator and require that the blood irradiator be placed immediately under the skin. T o overcome this limitation, a tube would extend from the blood irradiator to a pick up unit. Thus the blood irradiator would be deeply implanted such as in a segment of the abdominal aorta or iliac artery and the said tube extend to Said pick up unit immediately under the skin. The tube and said pick up unit would be coated by the said silicone rubber sealant. The pick up unit would contain a portion of the movement mechanism described above. For example, a sliding handle such as shown as 27 would be attached to a cable with lubricant, the cable with lubricant passing through said tube to the blood irradiator. Alternatively, the pick up unit might contain a bar magnet attached to an arm or drum which moves or screws a cable inside the said tube and which cable in turn moves or screws the radioactive element into place inside the blood irradiator. An alternative utilizing hydraulic principles would be for said pick up unit to contain a hydraulic piston with hydraulic fluid extending through said tube to the irradiator with its valve. The alternative utilizing electronic means would have an R-F sensor in the pick up unit with electric wires extending through the tube to the solenoid and its mechanism in the blood irradiator.

The device may be used to study the effects of chronic radiation of the blood and to treat human diseases such as leukemia, dysglobulinemias, and collagen-vascular diseases. Radioprotective drugs may also be studied for their modifying effects of the results of the radiation, and an animals or humans immunologic response may be blunted so as to permit organ or bone marrow transplantation.

Although a specific embodiment has been disclosed, it is obvious that changes may be made within the scope of the invention and we intend to be limited only by a broad interpretation of the appended claims.

We claim:

1. A blood irradiator comprising:

(a) a hollow tube having a window permeable to radiation;

(b) a shield that absorbs radiation surrounding said tube, said shield having a hollowed out portion communicating with said window;

(c) a radioactive element disposed within said hollowed out portion;

(d) a positioning means attached to said radioactive element; and

(e) said radioactive element being movable in said hollowed out portion by said positioning means from a position adjacent to said window to other positions whereby the amount of radiation that passes into said tube may be varied.

2. A blood irradiator according to claim 1 wherein said shield has a cavity on the exterior surface thereof and a tunnel communicating between said hollowed out portion and said cavity; and wherein said positioning means includes a cable attached to said radioactive element and lying in said tunnel and a handle located in said cavity and attached to said cable.

3. A blood irradiator according to claim 2 wherein said shield is composed of an interior part and an exterior part surrounding said interior part, said exterior part has a cavity; and including a handle located in said cavity and attached to said positioning means.

4. A blood irradiator according to claim 1 wherein said shield is composed of an interior part made from a material which stops beta particles and an exterior part surrounding. said interior part which absorbs Bremsstrahlung radiation produced by the beta particles.

5. A blood irradiator according to claim 1 including a coating surrounding said shield and being of a material inert to the body.

References Cited UNITED STATES PATENTS 2,968,734 1/1961 Yeomans 250 1o6 3,240,207 3/1966 Barker et a1. 12s 334 X 3,434,467 3/1969 Anderson et a1 12s 1.1

FOREIGN PATENTS 857,992 1/1961 Great Britain.

DALTON L. TRULUCK, Primary Examiner US. Cl. X.R. 

